From owner-freebsd-hackers Tue Aug 29 00:57:18 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id AAA16721 for hackers-outgoing; Tue, 29 Aug 1995 00:57:18 -0700 Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id AAA16713 for ; Tue, 29 Aug 1995 00:57:10 -0700 Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id JAA04925 for hackers@freebsd.org; Tue, 29 Aug 1995 09:49:29 +0200 From: Luigi Rizzo Message-Id: <199508290749.JAA04925@labinfo.iet.unipi.it> Subject: fdisk & disklabel troubles To: hackers@freebsd.org Date: Tue, 29 Aug 1995 09:49:29 +0200 (MET DST) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Content-Length: 3100 Sender: hackers-owner@freebsd.org Precedence: bulk I am having a hard time in understanding/using the parameters used in the disk-maintainance utilities (fdisk, disklabel, sysinstall etc.) since the introduction of slices (tried this on both 2.0.5-RELEASE and the 950726-SNAPSHOT). After spending a few hours on the above programs, I have more details which I hope somebody can clarify. I am starting with a fresh, full 950726-SNAPSHOT installation on wd0 (entire disk for freebsd) and an aborted install on wd2 (entire disk for freebsd, but just did the partition and newfs). I see that: * fdisk cannot read a valid partition table from either disk. The "bios idea" of the disk, as printed by fdisk, shows one cylinder less than the real size. * fdisk cannot write the partition table either (or at least, it cannot be read back!). I tried to set the correct parameters and write to disk, fdisk did not write any error message but reading again the partition table shows the same old values. (cannot do further experiments with working fdisks, but my setting is easily reproducible). * (BTW, the "usage" line of fdisk shows a "-r" flag which does not exist. Luckily, fdisk does not kill the system. With disklabel, things seem to be worse: whenever I try to write a label, the system reboots. As a reference, here are the different ideas of the disks: REAL: 1010 cyl, 12 hd, 55 sec, total 666.600 sectors fdisk: 1009 cyl, 12 hd, 55 sec, part. start 1, size 665.939 beg.: cyl.0 sec.2 hd.0 end: cyl.1009 sec.1 hd.0 disklabel: 1009 cyl, 12 hd, 55 sec, size 666.545 REAL: 1057 cyl, 16 hd, 63 sec, total 1.065.456 sectors fdisk: 1056 cyl, 16 hd, 63 sec, part. start 1, size 1.064.447 beg.: cyl.0 sec.2 hd.0 end: cyl.32 sec.1 hd.0 disklabel: 1056 cyl, 16 hd, 63 sec, size 1.065.393 I also tried to use /stand/sysinstall for formatting the disk, but without luck: the Write option in the partition editor does not work! I have played a little with the /sysinstall code (/src/release/sysinstall/disks.c) and found that, for some reason, the disk (in diskPartitionWrite()) is not "enabled", thus the MBR is not written to disk. However, I don't know how long the code will survive, and probably Jordan is the best candidate to fix it. So: does anyone know of a safe way to fdisk/disklabel a disk on 2.0.5 and newer releases ? I have already lost the partition table on two disks, and have killed the data on the disks by trying to fix them with fdisk &C. And now I am really scared on installing 2.0.5 rather than snap950322 on newer machines! Thanks Luigi ==================================================================== Luigi Rizzo Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it Universita' di Pisa tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 ====================================================================